The losses of the regulating member directly affect the quality of operation of a watch as well as its power reserve.
The regulating member is conventionally sensitive to the various vertical or horizontal positions of the watch, and differences between the flat/suspended positions are often significant.
Various attempts have been made in the past to omit the balance spring, mostly in static applications such as clocks or fluid counters.
GB Patent Application No 616969A in the name of CLEMEN JORGENSEN discloses a static application of a pendulum clock which is less sensitive to shocks and able to be moved safely. To this end, the return element of the regulating member is formed by a torsion wire anchored at both ends and carrying a balance in the middle thereof, the wire being located vertically. The tension of the wire is achieved via the resilience of its end supports. The useful length of the wire is limited at one of the ends thereof by a position adjustable fork, whose point of contact with the wire determines its useful length. The fork support may be a bimetallic strip to achieve temperature compensation.
Two documents: U.S. Pat. No. 3,635,013 in the name of A BERTSCH HANNS, and DE Patent No 251558C in the name of BRUNO KRAUSZE, also disclose regulators with torsion tubes, or with parallel-mounted torsion wires, or with a single torsion wire.
U.S. Pat. No. 5,772,803 in the name of PEKER ATAKAN discloses a spring made of an amorphous metal alloy, such as a helical spring, torsion beam or torsion tube, not particularly intended for a horological application.
Some documents describe metallic glass springs comprising a curvature: EP Patent Application No 2133756A2 in the name of ROLEX SA discloses a method for shaping a mainspring formed of a one-piece metallic glass ribbon, wherein the theoretical free shape to be given to the one-piece metallic glass ribbon is calculated so that each segment, once the spring is wound inside the barrel, is subjected to the maximum bending moment, the ribbon is shaped by being given curvatures characteristic of this theoretical free shape, to take into account the reduction in curvatures once the ribbon is released, the ribbon is relaxed to set the shape thereof by heating, and then the ribbon is cooled. This ROLEX document focuses on the case of a mainspring whose thickness is greater than 50 micrometers. The other Patent Application WO 2011/069273 A1 in the name of ROLEX SA discloses a method of producing a spring for a timepiece, of similar dimensions, including at least one one-piece metallic glass ribbon comprising at least one curvature, this method including a step of shaping said one-piece ribbon by plastic deformation to obtain at least one portion of said curvature. EP Patent Application No 2154581A1 in the name of ROLEX SA discloses a one-piece metallic glass mainspring with a thickness of more than 40 micrometers.